Question: When did Alexandra Fyodorovna marry when he was Nicholas II of Russia?
Paraphrase: What was the date that Alexandra Fyodorvna marry when he was Nicholas II of Russia?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q152094 p:P26 ?s . ?s ps:P26 wd:Q40787 . ?s pq:P580 ?value}